1. Field of the Invention
The present invention relates to a turning efficiency improving apparatus for an automotive vehicle of a type, in which at the time of emergency steering such as represented by, for example, obstacle avoidance, a difference in braking force or a difference in driving force is generated on inside and outside vehicle wheels with respect to turning with the use of braking force sources or driving force sources that can implement left and right separate controls, respectively, so that a yaw moment of the vehicle resulting from the braking/driving (braking and/or driving) force difference can be efficiently generated.
2. Description of Related Art
The turn assist utilizing the conventional braking force is disclosed in the patent document 1 listed below. According to the patent document 1, disclosed is a feed forward control in which a phase delay of the yaw moment of the vehicle is improved by the turn assist relying on the braking force.
[Patent Document 1] Japanese Patent No. 3788131
It has however been found that as shown in FIG. 5A, when a braking force difference is generated between the left and right vehicle wheels 1L and 1R so that the braking force on the vehicle wheel on the side inwardly with respect to the direction of turn or on the inside with respect to turning is rendered to be larger during the steering condition, the braking force is oriented towards the inside with respect to turning and, therefore, moment Ma in the direction of turn of the automotive vehicle and moment Mb counter to that direction of turn are simultaneously generated to counterbalance as shown in FIG. 5B. For this reason, the yaw moment cannot be efficiently generated and an effect of turn assist cannot therefore be obtained sufficiently. In view of this, without receiving any effect of turn assist, the vehicle wheel 1R must be forcibly turned as shown in FIG. 5C and, therefore, it is not efficient.